Machine for digging underground galleries

ABSTRACT

The invention relates to a machine for digging underground galleries. This machine comprises a framework displaceable in the gallery, at least a pair of homologous arms connected to this framework and adapted for swinging movements respectively about two substantially parallel axis, a toolholder on each arm and cutting tools on each toolholder, adapted to cut through a cutting face of the gallery. In this machine, each arm and the position of the latter of its toolholder are adapted for a swinging movement of this arm greater than 90* from a position in which the said arm is directed towards a lateral wall of the gallery, as far as a position in which the arm is directed towards the other lateral wall, while passing through a position in which the arm is parallel to the gallery&#39;&#39;s axial plane, the cutting tools passing continuously along the cutting face of the gallery.

United States Patent [15] 3,663,054 Dubois 1 May 16, 1972 [54] MACHINE FOR DIGGING 2,202,584 5/1940 Holmes .299/71 x UNDERGROUND GALLERIES 52,833,531 5/1958 Joy ,49 .675 3/l970 Kam -Emden et al. ..299 31 [72] Inventor: Michel A. Dubois, 70, rue Hamoir, La p Louvlere! Belg'um Primary Examinen-Ernest R. Purser [22] Filed: Man 24, 1970 ArtomeySughrue, Rothwell. Mion, Zinn & Macpeak [2]] Appl. No.: 22,287 [57] ABSTRACT The invention relates to a machine for digging underground 30] Foreign Application Priority Data galleries. This machine comprises a framework displaceable in Mar 25 1969 Great Britain 15 687/69 the gallery, at least a pair of homologous arms connected to 1969 Great Britain "6o977/69 this framework and adapted for swinging movements respectively about two substantially parallel axis, a toolholder on each arm and vcutting tools on each toolholder, adapted to cut [52] US. Cl ..299/l8, ll, through a cutting face of the g y In this machine each arm [51 1 Int cl E01 g 3/04 E2 29/02 and the position of the latter of its toolholder are adapted for a g g movement of this armgreater than 90 [58] Field of Search ..299/3l, 71, 18, 64-68 7 tion in which the said arm is directed towards a lateral wall of the gallery, as far as a position in which the arm is directed [56] References Cited towards the other lateral wall, while passing through a position UNITED STATES PATENTS in which the arm is parallel to the gallery's axial plane, the cutting tools passing continuously along the cutting face of the 3,446,535 5/1969 Lauber ..299/3l ll from a posi- 3,l2l,558 2/1964 Gonski et al.. ...299/71 X 2,422,053 6/1947 Tibbals ..299/7l X 12 Claims, 19 Drawing Figures PATENTEnmnsmrz 3,663,054

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v j I I 41 I 8 4? e 16 I, 56 v I I Q/ I 20% I 1 8 56 B I I] 5 I 10 I l 2o 3 x 3 6 I T 4O 22 I I, 2L: c I 3 1 d 1 I I 46 I 7 L, j 4 1 PATENTEDMM 16 I972 33, 663 O54 sum 11 or 15 PATENTEDMM 16 I972 sum 120F15 PATENTEBHAY 16 1912 3. 663 O54 SHEET 13UF 15 9ATENTEDMAY 16 I972 sum 150F157 1 5 v x 8 w 5 1/ 5 5 5 6- 5 f w 1 1 In N ill: a I wi 1 I 0' O NM. 6 2 f 4 v I R (I!!! 4m 0 0 2 1 w 1 ll M I 2 w 5 5 E 1 w M 2 MACHINE FOR DIGGING UNDERGROUND GALLERIES The present invention relates to a machine for digging underground galleries, comprising a framework displaceable in the gallery, at least a pair of homologous arms connected to this framework and adapted for swinging movements respectively about two substantially parallel axis, a toolholder on each arm and cutting tools on each toolholder, adapted to cut through a cutting face of the gallery.

Machines of this type present the advantage of allowing the digging of galleries having substantially a rectangular cross section. The edges of this section, which are perpendicular to the swinging axis of the homologous arms, are substantially linear.

Throughout the present specification, the terms "floor and roof of the gallery" designate both walls of the same, corresponding to these substantially linear edges of the cross section of the gallery.

In known machines of this type, the position of the toolholders on the pair of homologous arms and the respective positions of these arms on the framework allow only a swinging movement of each arm of about 90, from a position in which it is directed towards a lateral wall of the gallery as far as a position in which it is substantially parallel to the gallery's axial plane, and vice-versa.

With such a machine however, the tools of each toolholder are able to cut through the cutting face of the gallery only as they are swung from a lateral wall towards the axial plane of the gallery. This can be disadvantageous in case of cutting galleries through lightly cohesive formation, while it can occur the dislodging, from the central area of the cutting face, of blocks of rocks of excessive sizes, which are difficult to remove.

Further, in case of cutting through hard rocks, the beginning of the cutting operation from lateral walls is particularly difficult.

The object of this invention is to avoid this difficulty and to provide a machine which is further of a much greater efficiency.

For this purpose, in the machine according to the invention, each of the homologous arms and the position on the latter of its toolholder are adapted for a swinging movement of this arm greater than 90 from a position in which the arm is directed towards a lateral wall of the gallery as far as a position in which the arm is directed towards the other lateral wall, whilst passing through a position in which the arm is parallel to the gallery's axial plane, the cutting tools passing continuously along the cutting face of the gallery. Y

In the machine according to the invention, the swinging movement of each arm corresponds, for example, to 120 to 250. Under the action of the forces to which the cutting tools are subject during the swinging movements of the arms, these cutting tools act on the cutting face and from the latter cut a crescent-shaped rock chip" which disintegrates in step with its formation.

In the case in which the machine is driven forward in the gallery in such manner that the swinging axis are parallel to the vertical plane passing through the axis of the gallery, the roof and floor of the gallery will extend along two horizontal lines in cross section, which evidently facilitates the placing in position of the timbering and the laying of a rolling or rail track.

It is obviously possible to drive the machine forward in such manner that the swinging axis are oblique relative to the vertical plane passing through the axis of the gallery. This arrangement of the machine according to the invention may be useful for digging a gallery through a geological stratum, without impairing the integrity of at least one wall or delimitation of this geological stratum.

In the machine according to the invention, it is possible to turn sufficiently each arm towards any one lateral wall of the gallery for its toolholder being no more in contact with the cutting face of the gallery.

It is thus possible, with the machine of this invention, to displace forward the framework, towards this cutting face, even as homologous arms are directed towards the central plane of the framework.

The machine according to the invention is thus adapted for the toolholders cutting through the cutting face from the central part of this cutting face, as far as the lateral walls of the gallery, which avoids the disadvantages mentioned hereabove for machines of the prior art.

Throughout the specification, the expression operational cycle of a toolholder" relates to the displacement of the toolholder, from a first position in which its ann is directed towards a lateral wall of the gallery, as far as a second position in which this arm is directed towards the other lateral wall of the gallery and the going back as far as the first position, the toolholder passing continuously along the cutting face of the gallery between these two positions.

The working of the machine may thus be regulated for each toolholder cuts in the cutting face, only during one half of its operational cycle, for example during its displacement by the arm whereon it is carried, from the aforesaid first position as far as the aforesaid second position of this operational cycle. During the other half of its operational cycle, the toolholder does not act on the cutting face.

In case of a working of this kind for the machine, it is only after the toolholders have carried out a complete operational cycle, that the arms may be displaced towards the cutting face on a distance equal to the forward step chosen, i.e. on a distance equal to the maximum thickness of the rock chip" which is to be cut through the cutting face of the gallery. This forward step may be chosen before each forward displacement of the arms according to the actual rock cutting resistance.

The working of the machine may also be regulated so that each toolholder cuts through the cutting face during both parts of its operational cycle, i.e. on the one hand, during its displacement bythe arm whereon it is carried, from the first position as far as the second position and, on the other hand while it comes back from this second position as far as the first position.

In case of a working of this kind for the machine, the arms are to be moved forward in the gallery, on a distance equal to the forward step chosen, after each half of an operational cycle.

In the machine according to the invention, the cutting tools 1 may be, for example, picks, rotatable cutters, compressed air tools, hydraulic or pyrometric means, or any other toolsadapted to cut through a cutting face of a holder may be fixed or rotative on its arm.

According to a particular embodiment of the machine of this invention, in case of each tool holder is a rotatable toolholder, the latter can be mounted on its arm with its rotation axis substantially parallel to an axial plane of the arm. With gallery. Each toolsuch an embodiment, it is possible to arrange the cutting tools on each toolholder for these tools acting on the cutting face of the gallery approximately tangentially to their courses about the swinging axis of the arm of this toolholder. In this embodiment, it is particularly advantageous to use as cutting tools, cutting discs having one or more discs. Cutting discs are further usually more appropriate for digging in hard rock. In this embodiment, the forces required to drive the toolholders, all other conditions being identical moreover, are very much smaller than those needed to drive the toolholders of the known machines, which frontally act on the cutting face. Another advantage of this embodiment resides in the fact that no minimum number of cutting tools is mandatory.

All other things being equal, it is possible for this machine to require less power. As a result, it is less bulky, less heavy and consequently easier to handle.

In this particular embodiment of the machine of this invention, if the cutting tools are cutters of the single disc type, it is advantageous for these to be arranged in two or more stepped areas on each tool holder and it is possible to establish the optimum offset of the tools on the toolholder. This advantageous feature of this embodiment resides in the fact that, in this case, the tool holders act approximately tangentially on the cutting face and work along a narrow pass or cut. The removal of the waste or rubble is thus facilitated and directional control over the tool holders within the gallery is easier.

The optimum stepped or offset pattern of the cutters depends on the nature of the rock and the machine is advantageously contrived in such manner that this offset is adjustable.

Beyond the advantages cited hereinabove, the machine according to the invention greatly facilitates access to a tool holder, for example to replace a cutting tool of the same, without having to reverse the machine in the gallery. In this point of fact, it may be arranged in such a manner that the arms carrying the toolholders may be sufficiently turned alongside the sidewalls of the gallery, in such manner as to allow a removal and replacement of atool. To facilitate access to the toolholders, it is advantageous to build the machine in such manner as to contrive convenient passages between the framework of the machine and the lateral walls of the gallery. These passages may moreover be useful for the placing in position of the timbering, at a short distance from the cutting face.

As it is designed to the digging of broad galleries, the machine according to the invention may comprise more than a pair of homologous arms adapted to swing respectively about two parallel swinging axis. According to the breadth of the gallery to be dug, the machine may comprise, for example, three, four or more homologous arms adapted to swing respectively about three, four or more parallel swinging axis.

Moreover, according to the height of the gallery to be dug,

the machine according to the invention may comprise more than one arm for example two or three superposed arms able to swing about each swinging axis. It is thus possible with the machine of this invention to cut galleries of great crosssection by means of toolholders of small size, thereby reducing the stresses on each toolholder to a large extent.

In the case of a machine comprising more than one arm able to swing about each swinging axis, each arm may be mounted on a rotatable turret the axis of which is the swinging axis. The turrets of the superposed arms able to swing about each swinging axis may thus be individually displaced, for example by means of individual motors.

In the case of a machine having at least two superposed arms able to swing about each swinging axis and the superposed arms having to be displaced simultaneously about this swinging axis, it can be advantageous to fix these superposed arms on a common pillar of which a longitudinal axis is the swinging axis.

Each pillar may be mounted on the carriage for the latter being able to pivot about this pillar.

The invention relates also to a process for cutting underground galleries by using a machine according to the invention. This process comprises making each arm of the machine execute successive operational cycles.

The process according to the invention comprises further, after having made one arm or a group of superposed arms able to swing about a common swinging axis, to execute a complete operational cycle respectively one half of an operational cycle and before making the arm or group of superposed arms to execute a further complete operational cycle respectively the other half of an operational cycle moving forward the arm or group of superposed arms towards the cutting face of the gallery, for a distance substantially equal to a forward step chosen, the next swinging axis being maintained stationary until the arm or the group of superposed arms of this last swinging axis have completed a complete operational cycle respectively one half of an operational cycle.

In this process, the forward step may be advantageously chosen, before each forward movement of an arm or a group of superposed arms, according to the actual rock cutting resistance.

Features and details of the invention will emerge from the following description and accompanying drawings, which diagrammatically and by way of example only, illustrate some examples of the machine according to the invention and of its working. I

FIG. 1 is a diagrammatical plan view, partially sectioned, of a first form of embodiment of the machine according to the invention, whose toolholders act on the cutting face of a horizontal gallery in process of being cut, seen in section;

FIG. 2 is a side view of the embodiment of FIG. 1;

FIG. 3 is a front view of a toolholder of the machine of FIGS. 1 and 2;

FIG. 4 is a side view of the toolholder illustrated in FIG. 3;

FIG. 5 is a partial diagrammatical horizontal section through the cutting face of the gallery, this cutting face being acted upon by two cutting tools of the toolholder of FIGS. 3 and 4;

FIG. 6 is a partial'side view of a a toolholder;

FIG. 7 is a diagrammatical plan view illustrating respective sizes of an advantageous modified form of the machine of this invention;

FIG. 8 shows in front view, toolholders of two superposed arms able to swing about a common swinging axis on the machine according to the invention, these toolholders being coupled to one another by a torque transmission device;

FIG. 9 is a plan view of a evacuating device of rubble cuts, equipping the machine illustrated in FIGS. 1 and 2;

FIG. 10 is a front view of the cutting face of the gallery cut by means of the machine illustrated in FIGS. 1 and 2;

FIG. 11 is a section through a geological stratum traversed by a gallery cut by means of the machine of FIGS. 1 and 2;

FIG. 12 is a diagrammatical plan view, partially sectioned, of a second form of embodiment of the machine according to the invention, whose toolholders act upon the cutting face of a gallery in process of being cut,

FIG. 13 is a side view, partially sectioned, of the embodiment ofFIG. 12;

FIG. 14 shows in plan view, the machine of FIGS. 12 and 13, adapted for a particular type of working;

FIG. 15 shows in plan view, the machine of FIGS. 12 and 13, adapted for another type of working;

FIGS. 16 and 17 are diagrammatical plan views of a machine similar to that of FIGS. 11 and 12, respectively in two successive positions of the said machine during the cutting of the cutting face of the gallery according to a particular type of working;

FIG. 18 is a plan view, partially sectioned, of a third embodiment of the machine according to the invention, whose toolholders act on the cutting face of a horizontal gallery in process of being cut, seen in section,

FIG. 19 is a partial plan view, partially sectioned, of a fourth particular fixing of a tool on embodiment of the machine according to the invention, whose I toolholders act on the cutting face of process of being cut, seen in section.

In these figures, the same referential notations denote identical elements.

In a first form of embodiment, shown on FIGS. 1 and 2, the machine comprises a framework 1 on which a carriage 2 is slidable. The framework 1 is equipped with four pairs of jacks 3 which are intended to immobilize the framework 1 in a gallery 4 in process of being cut, whilst bearing against the roof 5 and the floor 6 of this gallery.

At the front, the carriage 2 is equipped with two lower a horizontal gallery in bearers 7 intended to uphold the same on the floor 6 and with two upper jacks 8 intended to immobilize the same in the gallery 4, whilst bearing against the roof 5 of the latter. At the rear, the carriage 2 is equipped with two pairs of jacks 9 intended to enhance its immobilization in the gallery 4, whilst bearing against the roof 5 and the floor 6 of the gallery, for this purpose.

The framework 1 and the carriage 2 are connectedby means of four jacks 10 which are articulated each at their two ends.

Carriage 2 carries two vertical pillars 36, 36', which are in prolongation of the bearers 7 and jacks 8. Two superposed arms 11 are arranged on the pillar 36 about which they can swing; two similar superposed arms 12 are arranged on the pillar 36 about which they can swing. Each arm 11 carries a toolholder 16 provided with cutting tools similarily each arm 12 carries a similar toolholder 17. The toolholders l6 and 17 are rotatable toolholders and are each mounted at the extremity of their arm 11 and 12 with their rotation axis substantially parallel to this arm. Thus, each toolholder continuously faces substantially the wall of the gallery towards which its arm is directed.

The cutting tools 20 are rotatable cutters of the single-disc type. There are six of these per toolholder. They are vvpreferably disposed on each toolholder for approximately facing the cutting face of the gallery. Each cutting disc 20 is thus approximately tangential to its course about the swinging axis of the arm of its toolholder.

The position of the arms 11 and 12, on the aforesaid pillars 36, 36 is such that by rotation around the axis of these pillars, these arms are entrained from a position in which the toolholders 16 of arms 11 substantially face the toolholders 17 of homologous arms 12, as far as a position in which these toolholders l6 and 17 substantially face the side walls 22 and 23 of the gallery 4, and vice-versa. During this rotation or swinging movement of the arms, the latter are passing through a position in which the toolholders are directed towards the forward part of the machine and the cutting face 24 of the gallery. The entrainment of the arms is arranged to be performed, for example, by means of jacks, or of an electric or fluidic motor.

During this rotation of the arms 11 and 12, the toolholders 16 and 17, are in rotation and the cutting discs 20 progressively act tangentially on the cutting face 24 of the gallery in four contiguous areas 25 and 26 having the form of spherical segments (FIG. 7). Between these spherical segments, the cutting face 24 has three spurs 29, 30 and 31 extending in the direction towards the entrance of the gallery 4 and along the axial plane of this gallery (FIG. 10). It is necessary to demolish the spurs which would otherwise impede the progress of the machine in the gallery 4. For this purpose, the carriage 2 carries three rock drills 32 at the level of the floor 6 and three analogous rock drills 32 at the level of the roof 5. These drills are impelled pneumatically for example, and are intended to cut the upper spur 29 along the roof 5 and the lower spur 31 along the floor. The carriage 2 is further equipped with corebrakers (not illustrated) in the form of a wedge or chisel. Under the action of the advance of the carriage 2 in the gallery, these core-brakers exert a lateral force on the spurs 29 and 31 which finally break off.

It is evident that other means could be used for demolishing these spurs 29, 30 and 31.

The machine illustrated in FIGS. 1 and 2 will operate according to the following working cycle: the jacks 3 of the framework 1 are wedged against the roof 5 and the floor 6 of the gallery 4. The carriage 2 whose jacks 8 an 9 are retracted, is displaced towards the cutting face 24 by means of the jacks 10 along a distance equal to the cutting step scheduled. At the same time, the toolholders 16 and 17, begin to be entrained around their corresponding swinging axis, so that the cutting discs 20 of the toolholders begin to act on the cutting face 24 substantially tangentially. When the carriage 2 has been displaced by a cutting step distance (illustrated at 47 in FIG. 5), it is immobilized in the gallery by means of the jacks 8 and 9. The arms 11 and 12, are then entrained around the pillars 36, 36, from a position in which the toolholders 16 face substantially the toolholders 17, as far as a position in which these toolholders are substantially face to face with the side walls 22 and 23 of the gallery. During this rotation of the arms around the pillars and of the toolholders around their corresponding rotation axis, the cutting discs 20 of each toolholder cut a crescent-shaped rock chip from the cutting face 24.

After this rotation of the arms, which can advantageously amount to close to 210, they are returned without cutting action to their initial starting position.

As the carriage 2 has been moved away from the framework 1, for a maximum distance allowed by the jacks 10, the jacks 3 of the framework 1 are released during the rotation of the arms 11 and 12, for their return to the initial starting position and this framework 1 is displaced towards the cutting face 24 by means of the jacks 10, along a distance equal to the broke of jacks 10. The jacks 3 are then wedged again against the roof 5 and the floor 6 of the gallery and the jacks 8 and 9 of the carriage 2 are freed. The machine is then ready to begin another working cycle.

It is easy to gain access to the tool holders 16 and 17, in the machine illustrated in FIGS. 1 and 2. In point of fact, by rotation of the arms 11 and 12, it is possible to bring these toolholders close to the side walls 22 and 23 of the gallery 4, in such manner as it can be possible to replace a faulty cutting disc. An operator can then easily pass between the machine and a side wall of the gallery to reach a toolholder.

The choice of the direction of cutting from the center of the gallery towards the walls, and the fact of omitting to exploit a working stroke in the opposite direction, are dictated by the fact that along the intersection of two adjacent cuts 25, 26, the cutting face 24 of the gallery presents two free faces which make very much easier the cutting in the rock than the beginning from the lateral walls 22 and 23. Further, such a proceeding eliminates any risk of an incontrolled stripping of the rock in a portrusion zone which is thus particularly brittle.

If the nature of the rock were to be such that difficulties of this kind need not be feared, it is obviously permissible to perform a cutting action also whilst turning from the sides towards the center of the gallery, and to work alternately in the two directions.

FIGS. 3,4,5 and 6 show particularly advantageous embodiments of a tool holder with its cutting discs 20. The cutting discs are situated in the peripheral part of the toolholder. They are contingently distributed in two stepped areas, each comprising three cutting discs. They are grouped moreover in three groups 15 of two cutting discs, each group comprising one cutting disc from each of the two aforesaid stepped areas. Relative to the direction of rotation X of the toolholder, the cutting disc of the outer area of each group precedes the cutting disc on the inner area (see FIG. 3). Relative to the direction of advance Y of the machine in the gallery, the cutting discs of the inner area (shown in thick lines in FIG. 5) are slightly ahead of the cutting discs of the outer area (shown in thin lines in FIG. 5). This stepping of the cutting discs 20 in two areas facilitates the cutting operation without impairing the extraction of the rubble.

To facilitate the action of the cutting discs 20 on the cutting face, it proved to be preferable to install these on their toolholder in such manner that their corresponding axis of rotation constitute substantially generatrix of a conical surface whose axis coincides approximately with the axis of rotation of the toolholder.

For providing an adequate clearance angle of each cutting disc on the cutting face of the gallery, the apex of this conical surface is, with respect to this cutting face, beyond the swinging axis of the arm carrying the toolholder of the cutting disc.

It was observed that for both discs of each group 15, the optimum spacing of the discs parallel to the direction of advance Y of the machine depends on the nature of the rock. To allow the adaptation of this spacing to the nature of the rock, the cases 21 wherein are engaged the shafts of the tools 20 (FIG. 4) are inserted into corresponding hollow casings of the toolholders and metal plates of definite thickness are placed in the bottom of these casings so that the penetration of these cases into these casings may be adjusted at will. Another adjusting device for example screws, may be employed instead of these metal plates.

It was also observed that, generally, for both cutting discs of each group 15, the optimum ratio between the spacing parallel to the Y-direction and the spacing transverse to this direction is constant, whatever may be the spacing parallel to the Y- direction. According to a particular form of embodiment shown on FIG. 6, the hollow casing 56 wherein the case 21 of each cutting tool 20 is inserted, is removably engaged into a corresponding recess 58 of the toolholder. This recess 58 comprises along each radial side, a face 57 which is inclined at substantially 45 degrees with respect to the rotation axis of the toolholder, towards the peripheral part of the machine. The casing 56 is provided with two flanges 59 adapted to cooperate with the inclined faces 57. Tooths or ribs are advantageously provided on the flanges 59 and through faces 57 for reinforcing the fixation of the casing 56 in recess 58. This fixation can be ensured by means of bolts 60. As hereinbefore explained, the position of the case 21 in the casing 56 may be regulated by plates 61 of definite thickness, placed in the bottom of this casing 56.

In front of each group 15 of two cutters 20, the toolholders are each equipped with finishing picks 33 and with oblique scrapers 34. The picks 33 are intended to plane the surface of the cutting face, to make the same more uniform. The scrapers 34 form protective screens for the two cutting discs 20 they precede, against waste dislodged by the cutting discs 20 preceeding these screens and thrown rearwards. I Moreover, at the level of the floor 6,'the scrapers 34 of the two lower toolholders 16 and 17 are employed to impel the waste cut into two circular bins 35 (FIGS. 2, 4 and 8) arranged on the floor, respectively around the two aforesaid pillars 36, 36'. These circular bins 35, at their periphery, have a sloping plane 37 intended to allow the waste impelled by the-scrapers 34 to pass from the floor 6 into the bins 35.

In each of the bins 35 is arranged a scraping tool 38 arranged on a sleeve 39 surrounding the pillar 36 or 36' corresponding to this bin. It is imparted to the scraping tool 38 a reciprocating rotary motion around the pillar, in such manner as, to impel the waste contained in its bin 35 towards a conveyor 40 over two ramps 41 and 42 disposed respectively in prolongation of the conveyor 40 and transversely to this conveyor.

The conveyors 40 (for example drag conveyors) propel the waste on to an axial conveyor 43 which evacuates these to the entrance of the gallery 4. This axial conveyor 43 is a conveyor belt, for example.

It is advantageous to co-ordinate the machine according to the invention with an auxiliary framework 44 situated behind the framework 1 of the machine. This auxiliary framework (partially illustrated in FIGS. 1 and 2) is equipped with four pairs of jacks 45 (of which two pairs only are apparent in the Figures) intended to immobilize the same in the gallery 4 by bearing, for this purpose, against the roof and the floor 6 of the gallery 4.

A jack 46 connects the auxiliary framework to the carriage 2 (FIG. I).

In particular, the auxiliary framework is intended to carry facilities which are not essential on the framework 1 and the carriage 2 (for example tanks containing the fluid for operation of the jacks, pumps, an electrical transformer, etc.) Thanks to this fact, it is possible to reduce the bulk of the framework 1 and of the carriage 2 in substantial manner, in particular to shorten these two elements, in such manner as to allow of a rotation of the assembly of the framework and carriage in the gallery, for the purpose of starting another gallery directed differently.

For rotating framework 1 and carriage 2 as a whole in the gallery, for example around pillar 36', the framework 1 is brought as close together with the carriage 2, to reduce the floor area of the machine to a minimum. The jacks 45 are wedged against the roof and floor of the gallery 4 to immobilize the auxiliary framework 44 therein. The jacks 3 of the framework 1 are released, as well as the jacks 9 of the carriage 2 and the jack 8 of this carriage, corresponding to pillar 36. Framework 1 and carriage 2 are then rotated inside the gallery by means of the jack 46, around the pillar 36, the jack 8 of this pillar being maintained wedged against the roof 5 of the gallery 4.

As explained hereabove, thanks to the presence of the auxiliary framework 44 behind the framework 1, it is possible to reduce considerably the bulk of the framework 1 and carriage 2. According to a particular feature of the machine, in each plane perpendicular to both swinging axis of arms 11 and 12, the maximum distance a (FIG. 7) between the rotation axis b about which framework 1 and carriage 2 are rotated (which can be the axis of pillars 36 36') and the periphery of framework 1, is lower than the distance 0 between the rotation axis b and the longitudinal axial plane of this framework 1, plus the distance d between each swinging axis and the longitudinal plane, plus the distance e between each swinging axis and the periphery of the toolholder of the arm of the swinging axis.

With such an advantageous embodiment, it is possible to rotate the assembly of framework 1 and carriage 2 inside the gallery, for starting another gallery which can be directed at right angle or even more.

To modify the gradient of a gallery in process of being cut, the jacks 8 of the carriage 2 are released, and the assembly of the framework 1 and carriage 2 is pivoted around bearers 7, by means of the jacks 9 of the carriage 2, and/or by means of the jacks 3 of the framework 1.

The auxiliary framework 44 may also be used for making the machine to pivot around both bearers 7 in view of modifying the gradient of the gallery. For this end, jacks 45 of this auxiliary framework are wedged against floor and roof of the gallery 4 and all jacks 3,8 and 9 of framework 1 and carriage 2 are released. The aggregate of the framework 1 and carriage 2 is then pivoted as a whole around both bearers 7, by means of the jack 46.

For allowing the aforesaid rotation around one or both bearers 7, it is preferable to connect each bearer 7 to the carriage 2 by an articulation means (not shown).

The auxiliary framework 44 moreover represents a safety element for immobilization of the machine in the case of cutting a gallery of considerable gradient.

In the proceeding description, the auxiliary framework 44 has been supposed to be connected to the carriage 2. While this disposition is preferable for reason of safety, it is well evident that this auxiliary framework 44 could be connected to the framework 1.

In the case of the machine hereabove described used with its pillars 36, 36 continuously parallel to a vertical plane, the gallery out has a vertical symmetry plane. In this case, the roof 5 and the floor 6 of the gallery correspond to two horizontal lines, in cross section.

It is evident that this is equally applicable to cut a gallery having an oblique symmetry plane. This may be advantageous if it is intended to cut a gallery through a geological stratum,

without cutting the roof or hanging wall. An analogous case 1 has been illustrated in FIG. 10.-

In the machine hereabove described and shown on FIGS. 1 and 2, the arrangement of the arms 11 and 12 on the pillars 36, 36' stationary and that the arms turn around these. Provision may equally be made for the case in which the arms are keyed on the pillars which are then entrained in rotation around their corresponding axis.

In a modified form of embodiment, each arm 11, I2 is integral with a turret which is mounted on the carriage for swinging movement.

In another modified form of embodiment, both superposed arms 11 or 12 able to swing about a common swinging axis are adapted for pivoting about this swinging axis in opposite directions, while remaining continuously in symmetrical positions. With such an embodiment, a good counterbalancing of the machine is obtained. In such a machine, both superposed arms of each swinging axis or respective motors of these superposed arms are for example, connected to one another by a synchronization transmission device known per se, adapted to maintain continuously both superposed arms is'symmetrical positions.

In case of both superposed arms able to swing about each swinging axis are stationary to one another (for example in may be contrived in such manner that these pillars are 

1. A machine for digging undergrouNd galleries, comprising: a framework; a toolholder; means for moving the framework forward in the gallery; at least two superposed pairs of arms connected to the framework and adapted to swing about two substantially parallel axes transverse to the forward movement of the framework, each arm being provided with a toolholder mounted for rotation at its extremity so that the toolholder can cut through the cutting face of the gallery when its respective arm swings about its axis from inside towards outside with regard to the framework, each arm plus its toolholder having a length, measured from the swinging axis of its arm, greater than half the distance between both swinging axes, but less than the distance; at least a pair of carriages connected to the framework and supporting respectively both arms of each pair of arms, the carriages being adapted to slide on the framework, parallel to the forward movement of the framework, whereby both arms of the pair are individually movable forwardly and rearwardly on the framework; means for individually driving both carriages forwardly and rearwardly on the framework; and means for making both arms of the pair swing individually about both axes, from a position for which the arms are turned inside, with their respective toolholders in the rear of the intersection line of their respective circular displacements about the axes, of a length at least equal to the cutting step, towards a position for which these arms are turned outside, the toolholder of each arm cutting through the face of the gallery only when it is swung from inside towards outside, whereby it is possible to use the machine continuously.
 2. A machine for digging underground galleries, comprising: a framework; a toolholder; means for feeding the framework forward in the gallery; at least a pair of superposed pairs of arms connected to the framework and adapted to swing about two substantially parallel swinging axes transverse to the forward movement of the framework, each arm being provided with a toolholder mounted for rotation at its extremity, so that the toolholder can cut through the cutting face of the gallery when its respective arm swings about its swinging axis from inside towards outside with regard to the framework, each arm plus its toolholder having a length, measured from the swinging axis of its arm, greater than half the distance between both swinging axes, but less than the distance; means for individually immobilizing both swinging axes with respect to the framework; a single carriage articulated to the framework and supporting the arms; articulated driving means connecting the carriage to the framework, for producing alternative rotations of the carriage successively about one of both axes and about the other one, this axis being first immobilized, whereby both axes can be alternately displaced forward of a length substantially equal to the cutting step, and means for making both arms of the pair of arms to swing individually about both axes, from a position in which the arms are turned inside, with their respective toolholders in the rear of the intersection line of their respective circular displacements about the swinging axes, of a length at least equal to the cutting step, towards a position for which these arms are turned outside, the toolholder of each arm cuts through the face of the gallery only when it is swung from inside towards outside, whereby the machine can function continuously.
 3. A machine for digging underground galleries comprising: a framework; a toolholder; means for feeding the framework forward in the gallery; at least a pair of arms connected to the framework and adapted to swing respectively about two substantially parallel swinging axes transverse to the forward movement of the framework, each arm being provided with a toolholder mounted for rotation at its extremity, so that the toolholder can cut through the cutting face of the gaLlery when its arm swings about its swinging axis from inside towards outside with regard to the framework, each arm plus its toolholder having a length, measured from the swinging axis of this arm, greater than half the distance between both swinging axes, but less than the distance; means for individually and alternately displacing both swinging axes forward to a length substantially equal to the cutting step; means for individually driving both carriages forward and rearward on the framework; and means for making both arms of the pair of arms to swing individually about both axes, from a position for which the arms are turned inside, with their respective toolholders in the rear of the intersection line of their respective circular displacements about the swinging axes, of a length at least equal to the cutting step, towards a position for which these arms are turned outside, the toolholder of each arm cuts through the face of the gallery only when it is swung from inside towards outside, whereby the machine can work continuously.
 4. A machine for digging underground galleries comprising: a framework; a toolholder; means for feeding the framework forward in the gallery; at least a pair of arms connected to the framework and adapted to swing respectively about two substantially parallel swinging axes transverse to the forward movement of the framework, each arm being provided with a toolholder mounted for rotation at its extremity, so that the toolholder can cut through the cutting face of the gallery when its arm swings about its swinging axis from inside towards outside with regard to the framework, each arm plus its toolholder having a length, measured from the swinging axis of the arm, up to half the distance between both swinging axes; an additional digging device provided on the framework between both swinging axes, and adapted for cutting through the face of the gallery in the mediane zone of this gallery; means for moving forward simultaneously both swinging axes, a length equal to the cutting step, and means for moving both arms to swing simultaneously and symmetrically about the axes, from a position in which the arms are turned inside, with their respective toolholders in the rear of the extreme forward position achieved by the additional digging device in front of the framework, of a length at least equal to the cutting step, towards a position for which these arms are turned outside, the toolholders of both arms of each pair cut simultaneously through the face of the gallery, only when they are swung from inside towards outside, whereby it is possible to use the machine in a continuous manner.
 5. A machine as claimed in claim 4, wherein the means for moving simultaneously both swinging axes forwardly include: a carriage slidably mounted on the framework, parallel to the forward displacement of the framework, the carriage supporting the arms, and means for driving the carriage forward and rearward on the framework.
 6. A machine as claimed in claim 4, wherein each rotatable toolholder has its rotation axis substantially parallel to the arm on which it is carried, and is provided with rotatable cutting discs mounted on the toolholder in such a manner that the rotation axes of the discs constitute substantially a generatrix of a conical surface the apex of which is approximately on the rotational axis of the toolholder, beyond the swinging axis of the arm carrying the toolholder, the discs acting on the cutting face of the gallery approximately tangentially to their circular courses about the swinging axis of the arm carrying the toolholder.
 7. A machine as claimed in claim 6, wherein the cutting discs of each toolholder are situated in the peripheral part of the toolholder and are contingently distributed in at least two substantially coaxial stepped areas.
 8. A machine as claimed in claim 7, wherein the offset of each cutting disc of one area with respect to the discs of the next area is adjustaBle parallel and transverse to the rotation axes of the discs.
 9. A machine as claimed in claim 8, further including a case removably inserted into a corresponding hollow casing of the toolholder and mounting a cutting disc, a removable gauged plate being inserted between the case and the bottom of the casing in order to adjust offset, parallel to the rotation axis of the disc.
 10. A machine as claimed in claim 9, wherein the casing has a part oblique with respect to the rotation axis of the disc, the oblique part being removably applied against a corresponding oblique part of the toolholder, the casing being displaceable on the toolholder, parallel to the oblique parts, for adjusting the offset of the disc simultaneously parallel and perpendicular to the rotation axis of the disc.
 11. A machine as claimed in claim 4, further including an evacuating means for rubble cut having: a pair of circular bins disposed respectively around both swinging axes, at the level of the floor of the gallery; a sloping plane member in front of each circular bin, for allowing rubble cut to pass from the floor of the gallery into the bin; at least one oblique scraper on each arm adjacent to the floor of the gallery, for pushing the rubble cut towards the bin; a conveyor in the vicinity of each bin, for conveying the rubble cut from this bin towards the rear of the framework; at least one ramp in each bin, in the vicinity of its contiguous conveyor, for allowing the rubble cut to pass from the bin onto the conveyor, and a scraping tool displaceable inside each bin, in rotary reciprocating movement about the swinging axis corresponding to the bin, whereby the rubble cut can be pushed from this bin onto the contiguous conveyor, along the ramp of the bin.
 12. A method for cutting underground galleries of substantially rectangular section by using a machine having: a framework; a toolholder; means for feeding the framework forward in the gallery; at least a pair of arms swingable on the framework respectively about two substantially parallel swinging axes transverse to the forward movement of the framework, and provided each with a toolholder mounted for rotation at the extremity of the arm, so that the toolholder can cut through the cutting face of the gallery when its arm swings about its swinging axis from inside towards outside with regard to the framework, each arm plus its toolholder having a length, measured from the swinging axis of this arm, greater than half the distance between both swinging axes, but less than the distance, the method comprising the successive steps of: moving one arm of the pair of arms to swing about one of the swinging axes, successively first from inside towards outside, so that the toolholder of this arm makes one cut through the face of the gallery, and then from outside towards inside without acting on the cutting face; maintaining the one arm still about its swinging axis, and moving forward the axis towards the face of the gallery, on a distance substantially equal to the cutting step chosen, and during this forward movement, continuing to move the other arm of the pair so as to swing about the other swinging axis, swinging successively first from inside towards outside, so that the toolholder of this arm makes one cut through the face of the gallery, and then from outside towards inside without acting on the cutting face. 